EFINEA is the unsurpassed leader in supplying nickel-iron alloys to the industry. You will find Invar® and Free-Cut Invar “36”® Alloy FM (Free Machining grade) individual property tables for evaluating these two alloys. As a reference we have provided the comprehensive thermal expansion data, physical and mechanical properties, chemistry, and applicable specifications for Invar and Free-Cut Invar “36”.
To download an Invar® alloy data sheet, a Free-Cut Invar “36”® Alloy FM data sheet, or any other Controlled Expansion Alloy data sheets, please go to the Data Sheets section in our Technical Library.
Invar Average Coefficient of Thermal Expansion µm/m • °C |
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|---|---|---|---|
| Temperature Range °C | UNS NO. K93603, 871°C 1 hour, Furnace Cool | Temperature Range °C | UNS NO. K93603, 871°C 1 hour, Furnace Cool |
| 30 to 100 | 1.93 | 30 to 300 | 6.05 |
| 30 to 150 | 2.38 | 30 to 350 | 7.51 |
| 30 to 150 | 1.2 to 2.7* | 30 to 400 | 8.69 |
| 30 to 200 | 3.03 | 30 to 500 | 10.47 |
| 30 to 250 | 4.36 | 30 to 600 | 11.75 |
| Source: *ASTM F1684-06 (2021) Table 5; Average linear coefficient range limits; ASTM F1684-06 (2021) Table X2.1 | |||
To compare the average linear coefficient of thermal expansion across our line of controlled expansion glass and sealing alloys, please refer to the Thermal Expansion Table.
Invar Typical Physical Properties | ||
|---|---|---|
| Density | lb/cu in | 0.291 |
| Specific Gravity | 8.05 | |
| Curie Temp | °F | 535 |
| °C | 279.4 | |
| Melting Range | °F | 2600 |
| °C | 1427 | |
| Electrical Resistivity (70°F) | ohm-cir mil/ft | 495 |
| microhm-cm | 82.92 | |
| Thermal Conductivity | BTU-in/sq. ft-hr-°F | 72.85 |
| W/m °C | 10 | |
| Mean Specific Heat | BTU/lb/°F | 0.123 |
| Source: CarTech Invar 36 Alloy Data Sheet v.3/15/04 |
Invar Typical Mechanical Properties | ||
|---|---|---|
| Tensile Strength | ksi | 58 min. - 72.5 max. |
| MPa | 400 min. - 500 max. | |
| Yield Strength | ksi | 33.33 min. - 50.7 max. |
| MPa | 230 min. - 350 max. | |
| Elongation | % in 2" | 34 |
| Hardness | Rockwell HRB | B60 min. - 85 max. |
| Modulus of Elasticity | ||
| • Annealed Bar & Strip | ksi | 20.5 x 103 |
| • Cold Rolled | ksi | 21.5 x 103 |
| Source: ASTM F1684-06 (2021) Table 4 Plate |
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Invar Chemistry | |
|---|---|
| Iron nominal | BalanceA |
| Nickel nominal | 36A |
| Cobalt max. | 0.50 |
| Manganese max. | 0.60 |
| Carbon max | 0.05 |
| Silicon max. | 0.40 |
| Phosphorus max. | 0.015 |
| Sulfur max. | 0.015 |
| Chromium max. | 0.25 |
| Aluminum max. | 0.10B |
| Magnesium max. | 0.10B |
| Zirconium max. | 0.10B |
| Titanium max. | 0.10B |
| Source: ASTM F1684-06 (2021) UNS K93603 Table 1 | |
| A The iron and nickel requirements are nominal. B The total of aluminum, magnesium, titanium, and zirconium shall not exceed 0.20% | |
Invar Specifications | |||
|---|---|---|---|
| Standard Grade | |||
| ASTM F1684 | AMS 1-23011 CL 7 | MIL-1-23011 CL 7 | UNS K93603 (Plate, Sheet) |
Free-Cut Invar “36”® Alloy FM
Free-Cut Invar "36"® Alloy FM Mean Coefficient of Thermal Expansion |
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|---|---|---|---|
| Temperature 77°F to | Coefficient x 10-6/°F | Temperature 25°C to | Coefficient x 10-6/°C |
| 212 | 0.91 | 100 | 1.64 |
| 302 | 1.32 | 150 | 2.38 |
| 392 | 1.69 | 200 | 3.04 |
| 482 | 2.34 | 250 | 4.21 |
| 572 | 3.26 | 300 | 5.87 |
| Source: CarTech Free-Cut Invar "36" Alloy Data Sheet v.3/15/04 | |||
Free-Cut Invar "36"® Alloy FM Free-Cut Typical Physical Properties | ||
|---|---|---|
| Density | lb/cu in | 0.291 |
| Specific Gravity | 8.05 | |
| Curie Temp | °F | 535 |
| °C | 280 | |
| Melting Point | °F | 2600 |
| Electrical Resistivity (70°F) | ohm-cir mil/ft | 495.0 |
| Thermal Conductivity | BTU-in/sq. ft-hr-°F | 72.6 |
| W/m °C | 10 | |
| Mean Specific Heat | BTU/lb-°F | 0.1230 |
| Source: CarTech Free-Cut Invar “36” Alloy Data Sheet v.3/15/04 | ||
Free-Cut Invar "36"® Alloy FM Typical Mechanical Properties |
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|---|---|---|---|
| Annealed Bars | Cold Drawn Bars | ||
| Tensile Strength | ksi | 65 | 90 |
| MPa | 448 | 621 | |
| Yield Strength | ksi | 40 | 70 |
| MPa | 276 | 483 | |
| Reduction in Area | % | 65 | 60 |
| Elongation | % in 2" | 35 | 20 |
| Hardness | Rockwell B | 70 | 90 |
| Modulus of Elasticity | ksi | 20.5 | 21.5 |
| Source: CarTech Free-Cut Invar "36" Alloy Data Sheet v.3/15/04 | |||
Free-Cut Invar "36"® Alloy FM Free-Cut Chemistry | |
|---|---|
| nominal % unless noted | |
| Iron | Bal |
| Nickel | 36.00 |
| Manganese | 0.90 |
| Silicon | 0.35 |
| Cobalt | 0.20 |
| Selenium | 0.20 |
| Source: CarTech Free-Cut Invar “36” Alloy Data Sheet v.3/15/04 |
Free-Cut Invar "36"® Alloy FM Specifications |
|
|---|---|
| Free Machining Grade Round Bar, Rod | |
| ASTM F1684 | UNS K93050 |
For additional information on specifications of the materials distributed by EFINEA, please visit the websites of the international organizations that develop and publish technical standards: ASTM International and ASM International.